The present invention relates to a utility meter reading system for use with a meter which measures the consumption or use by a consumer of a metered commodity or service and, more particularly, to such a system including a dial arrangement which permits the meter to be read by a noncontact shaft angle detector and, simultaneously, visually read by the consumer or by a utility company employee.
It has long been recognized that automated reading of utility company meters, such as electric and gas utility meters, would be highly desirable. One of the major obstacles to implementing automated meter reading systems has been the relatively high cost of the meter reading apparatus which must be provided for each meter to be read. In a typical electric or gas utility system having thousands of meters, minimizing individual meter apparatus costs is essential to an economically viable automated reading system, and the ability to retrofit existing meters is highly desirable. Converting the large number of existing utility meters to automatic meter reading capability with minimum modification to the meters has presented substantial difficulties.
Disclosed in U.S. patent application Ser. No. 747,243, filed June 21, 1985, entitled Meter Reading Methods and Apparatus, by Burrowes, now U.S. Pat. No. 4,646,084, issued Feb. 24, 1987, and assigned to the assignee of the present invention, is an improved automated meter reading device which permits a meter to be retrofitted with minimal changes to the meter structure. A noncontact shaft angle detector arrangement optically reads the angular positions of the meter dial shafts, thus eliminating the need for any mechanical modification to the meter mechanism or mechanical coupling between the meter and the reading apparatus which is added to the existing meter structure. A patterned disc is mounted for rotation with each of the dial pointers and indicator shafts. The patterned discs are illuminated in sequence and their orientations are read by a sensor. The angular positions of the indicator shafts are determined in this manner to provide a complete reading of the meter. Output signals are then produced by the electronics to transmit the meter readings and other information to remote locations. This meter reading system is superior to prior art systems since it may easily be coupled to known, dependable meter mechanisms without requiring significant mechanical modifications to the mechanisms beyond the addition of the patterned discs. Additionally, such a meter reading arrangement can be added to existing meters in the field, retrofitting them in a simple, economical fashion to form a part of the automated meter reading system.
In the meter reading arrangement disclosed in the application Ser. No. 747,243 the radiant energy sensor arrangement, including energy source and optics, is mounted close to the patterned discs and dial pointers, making visual reading of the meter somewhat difficult. A viewing window to permit visual inspection of the meter is necessarily provided to one side of the row of discs and dial pointers, providing an oblique viewing angle.
Accordingly, there is a need for a utility meter reading system, including a dial arrangement which may be monitored by a noncontact shaft angle detector and simultaneousy visually inspected.